An improvised pipe bomb discovered close to Colombo's main airport was successfully diffused by the Sri Lanka airforce, police said.

Soldiers stand guard at the Bandaranaike International Airport in Colombo, Sri Lanka, April 22, 2019. (Photo: Xinhua)

A police source told AFP that a "homemade" pipe bomb had been found late Sunday on a road leading towards the main terminal, which remains open with heavy security after deadly attacks on churchs and hotels.

Airforce spokesperson Group Captain Gihan Seneviratne said the IED was believed to be locally manufactured.